Cargo planes carrying shipments of gold are disappearing. No wreckage can be found and there is no communication from the pilots. Sergeant Renfrew (James Newill) of the Canadian Royal Mounted Police is ordered to patrol the air and escort the shipments. Unknown to the Sergeant, dangerous criminals are developing a deadly ray gun that disrupts electrical impulses, causing planes to lose control and fall from the sky. To increase the ray's power, the criminals hire the world's leading scientist, Professor Lewis, telling him that he'll be working on a top-secret government project. When the Professor learns the truth, the gang holds him hostage and threatens the life of his daughter.